HP41, N battery (N Cell), charging of HR1

[Bill (Smithville NJ)]

(10-09-2020 09:12 PM)Dave Frederickson Wrote:  Finally, that was a spectacular explosion!

Reminds me of when I was young and devised a way to recharge my 9v battery for my transistor radio. I had rigged up a transformer and a half wave rectifier. The transformer was out of an old TV so not sure what it's voltage was. But it was a lot!

I found through experimenting that I could connect the 9v battery to the circuit and charge it for about ten seconds. At that point it was boiling hot to the touch. It would run the radio for about another week.

One time I got distracted, and the battery exploded. It sent the metal casing across the room and embedded itself about a half inch into the plaster board wall. It was quite exciting!

This was in 1960 and I was about 11 years old. I found experimenting with electricity a lot of fun. (And I did receive plenty of bad shocks).

73
Bill
WD9EQD
Smithville, NJ